Writing instrument



FIG. 1 is a front view of an embodiment of a writing instrument showing a new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a side view thereof;

FIG. 4 is another side view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The oval and the design contained therein shown in broken lines in FIGS. 1–4 show environment and form no part of the claimed design. 

The ornamental design for a writing instrument, substantially as shown and described. 